Structure-Dependent Photophysical Properties of Singlet and Triplet Metal-to-Ligand Charge Transfer States in Copper(I) Bis(diimine) Compounds

2003 ◽  
Vol 42 (20) ◽  
pp. 6366-6378 ◽  
Author(s):  
Zainul Abedin Siddique ◽  
Yuichi Yamamoto ◽  
Takeshi Ohno ◽  
Koichi Nozaki
Keyword(s):  
Charge Transfer ◽  
Photophysical Properties ◽  
Ligand Charge Transfer

Synthesis, Characterization and Photophysical Properties of Rhenium(I) Complexes Containing 4,5-Diazafluorene Ligan

2011 ◽  
Vol 239-242 ◽  
pp. 2612-2615
Author(s):  
Jie Xiu Wang ◽  
Feng Zhao
Keyword(s):  
Charge Transfer ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Absorption And Fluorescence Spectra ◽  
Rhenium Complexes ◽  
H Nmr ◽  
Ligand Charge Transfer

Two related tricarbonyl rhenium complexes with the formula of [Re(CO)3(L)Cl], where L=4,5-diazafluoren-9-one (Dafo-Re) and 9-(phenylamino)-4,5-diazafluoren (PADF-Re) were successfully synthesized with the aim to explore the effect of the geometry of Dafo on Rhenium(I) coordination, and characterized by1H NMR. Photophysical behaviors are investigated by UV–vis absorption and Fluorescence spectra. The two complexes Dafo-Re and PADF-Re show metal-to-ligand charge transfer absorptions at ca.391nm, ca.394 nm and emissions at ca.492nm, ca.470nm, respectively.

Synthesis, Characterization and Photophysical Properties of Thiophene-Containing Chloro Re(I) Complex

2010 ◽  
Vol 146-147 ◽  
pp. 869-872
Author(s):  
Jie Xiu Wang ◽  
Feng Zhao
Keyword(s):  
Charge Transfer ◽  
Electron Density ◽  
1H Nmr ◽  
Photophysical Properties ◽  
Red Shift ◽  
Rhenium Complexes ◽  
Diimine Ligands ◽  
Ligand Charge Transfer

Two tricarbonyl rhenium complexes with the formula of [Re(CO)3(L)Cl], where L=1,10-phenanthroline (Phen-Re) and 2-(3-thienyl)-imidazo[4,5-f]-1,10-phenanthroline (TIPh-Re), were successfully synthesized and characterized by 1H NMR and UV–Vis with the aim to analyze the effect of the thiophene(TI) moiety on the photophysical properties of TIPh-Re. It was found that the introduction of an π-electron density moiety into diimine ligands leads to a dramatic red shift of the absorption of the corresponding Re(I) complex. At the same time, the results verify that the triplet metal-to-ligand charge-transfer dπ(Re)→π*(N-N) emission (3MLCT) of Phen-Re and TIPh-Re centered at ca. 566 nm and ca.569 nm, respectively.

Metal-to-Ligand Charge Transfer Excited States in π-Conjugated Systems

2001 ◽  
Vol 665 ◽  
Author(s):  
Yiting Li ◽  
C. Ed Whittle ◽  
Keith A. Walters ◽  
Kevin D. Ley ◽  
Kirk S. Schanze
Keyword(s):  
Optical Properties ◽  
Charge Transfer ◽  
Excited States ◽  
Transition Metal Complexes ◽  
Transient Absorption ◽  
Photophysical Properties ◽  
Transient Absorption Spectroscopy ◽  
Conjugated Oligomers ◽  
Conjugated Systems ◽  
Ligand Charge Transfer

ABSTRACTThis paper overviews recent work that examined the optical properties of mono-disperse, PPE-based π-conjugated oligomers that contain a 2,2-bipyridine-5,5'-diyl metal coordinating unit. The photophysical properties of the free oligomers and metallated oligomers that contain the -Ru(bpy)22+ and -Re(CO)3Cl transition metal complexes coordinated to the bpy-diyl unit have been characterized by absorption, photoluminescence and transient absorption spectroscopy. In addition, we report the photophysics of a novel organometallic “square” that features “sides” consisting of a PPE-type π-conjugated oligomer and “corners” that consist of (dbubpy)PtII(acetylide)2 units (where dbubpy = 4,4'-di-tert-butyl-2,2'-bipyridine).

scholarly journals Ruthenium(II)-bis(4′-(4-ethynylphenyl)-2,2′:6′, 2″-terpyridine) — A versatile synthon in supramolecular chemistry. Synthesis and characterization

2011 ◽  
Vol 9 (6) ◽  
pp. 990-999 ◽  
Author(s):  
Ronald Siebert ◽  
Florian Schlütter ◽  
Andreas Winter ◽  
Martin Presselt ◽  
Helmar Görls ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Supramolecular Chemistry ◽  
Photophysical Properties ◽  
Resonance Raman Spectroscopy ◽  
Bathochromic Shift ◽  
Resonance Raman ◽  
Electronic Effects ◽  
Charge Transfer Transition ◽  
Click Reactions ◽  
Ligand Charge Transfer

AbstractA homoleptic ethynyl-substituted ruthenium(II)-bisterpyridine complex representing a versatile synthon in supramolecular chemistry was synthesized and analyzed by NMR spectroscopy, mass spectrometry and X-ray diffractometry. Furthermore, its photophysical properties were detailed by UV/Vis absorption, emission and resonance Raman spectroscopy. In order to place the results obtained in the context of the vast family of ruthenium coordination compounds, two structurally related complexes were investigated accordingly. These reference compounds bear either no or an increased chromophore in the 4′-position. The spectroscopic investigations reveal a systematic bathochromic shift of the absorption and emission maximum upon increasing chromophore size. This bathochromic shift of the steady state spectra occurs hand in hand with increasing resonance Raman intensities upon excitation of the metal-to-ligand charge-transfer transition. The latter feature is accompanied by an increased excitation delocalization over the chromophore in the 4′-position of the terpyridine. Thus, the results presented allow for a detailed investigation of the electronic effects of the ethynyl substituent on the metal-to-ligand charge-transfer states in the synthon for click reactions leading to coordination polymers.

Temperature dependence of photophysical properties of a dinuclear C^N-cyclometalated Pt(ii) complex with an intimate Pt–Pt contact. Zero-field splitting and sub-state decay rates of the lowest triplet

2018 ◽  
Vol 20 (38) ◽  
pp. 25096-25104 ◽  
Author(s):  
Joseph C. Deaton ◽  
Arnab Chakraborty ◽  
Rafal Czerwieniec ◽  
Hartmut Yersin ◽  
Felix N. Castellano
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Photophysical Properties ◽  
Decay Rates ◽  
Zero Field ◽  
Triplet Excited State ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Ligand Charge Transfer ◽  
Metal Metal

A dinuclear Pt(ii) complexes exhibits an unusually large zero field splitting in its metal–metal-to-ligand charge transfer triplet excited state.

scholarly journals Ligand-Metal Charge Transfer Induced via Adjustment of Textural Properties Controls the Performance of Single-Atom Catalysts During Photocatalytic Degradation

2021 ◽  
Author(s):  
Jiaxu Liu ◽  
Yajun Zou ◽  
Daniel Cruz ◽  
Aleksandr Savateev ◽  
Markus Antonietti ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Heterogeneous Catalysts ◽  
Photophysical Properties ◽  
Organic Pollutant ◽  
Textural Properties ◽  
Single Atom ◽  
Single Atoms ◽  
Ligand Charge Transfer ◽  
Kinetic Investigations

Because of their peculiar nitrogen-rich structure, carbon nitrides are convenient polydentate ligands for designing single-atom-dispersed photocatalysts. However, the relation of catalysts textural properties with their photophysical properties and as a result activity in photocatalytic applications is rarely elaborated. Herein we report the preparation and characterization of a series of single-atom heterogeneous catalysts featuring highly-dispersed Ag and Cu species on mesoporous graphitic C<sub>3</sub>N<sub>4</sub>. We show that adjustment of materials textural properties and thereby metal single atoms coordination mode enables ligand-to-metal (LMCT) or ligand-to-metal-to-ligand charge transfer (LMLCT), a property tha was long speculated in single-atom catalysis but never observed. We employ the developed materials in the degradation of organic pollutant under irradiation with visible light. Kinetic investigations under flow conditions show that single atoms of Ag and Cu decrease the amount of toxic organic fragmentation products, while leading to a higher selectivity towards full calcination. The results correlate with the selected mode of charge transfer in the designed photocatalysts and provide a new understanding of the surface state of single-atom catalysts. The concepts can be exploited further to rationally design and optimize other single-atom materials.

Tuning Color of Charged Iridium (III) Complexes with a Spiro N,N'-Bidentate Ligand

2012 ◽  
Vol 229-231 ◽  
pp. 192-196 ◽  
Author(s):  
Kattaliya Mothajit ◽  
Kittiya Wongkhan ◽  
Rukkiat Jitchati
Keyword(s):  
Charge Transfer ◽  
Photophysical Properties ◽  
Bidentate Ligand ◽  
Organic Light Emitting Diodes ◽  
Photoluminescence Spectra ◽  
Absorption Bands ◽  
Light Emitting ◽  
Organic Light ◽  
Ligand Charge Transfer ◽  
Emission Color

Organic light emitting diodes (OLEDs), charged iridium(III) complexes, spiro ligand Abstract. We report the synthesis, characterization and photophysical properties of a cationic cyclometalated Ir(III) complexes of general formula [Ir(ppy)2(spbpy)]+Cl, [Ir(diFppy)2(spbpy)]+Cland [Ir(thiopy)2(spbpy)]+Clwhere ppy, spbpy, diFppy and thiopy are 2-phenylpyridine, 4,5-diaza-9,9′-spirobifluorene, 2-(2′,4′-difluorophenyl)-pyridine and 2-(thiophen-2′-yl)-pyridine, respectively. The complexes exhibit strong absorption bands in the UV region in solution spectra, due to spin-allowed ligand-centred (LC) and weaker absorption bands at longer wavelengths from metal-to-ligand charge transfer (MLCT). The photoluminescence spectra of all the complexes were characterised by a combination of 3MLCT and3π→π*states. The emission color of a cationic cyclometalated Ir(III) complexes in solution have successfully tuned from green to orange (501-582 nm).

A one-dimensional manganese(III)–porphyrin coordination polymer: crystal structure and photophysical properties

2020 ◽  
Vol 76 (5) ◽  
pp. 375-380
Author(s):  
Wen-Tong Chen
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Coordination Polymer ◽  
Hydrothermal Reaction ◽  
Photophysical Properties ◽  
Ethanol Solution ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
Dimensional Network ◽  
Ligand Charge Transfer

A novel manganese(III)–porphyrin complex, namely, catena-poly[[chloridomanganese(III)]-μ2-5,10,15,20-tetrakis(pyridin-3-yl)-21H,23H-porphinato(2−)-κ5 N 21,N 22,N 23,N 24:N 5], [MnCl(C40H24N8)] n , 1, was prepared by the hydrothermal reaction of manganese chloride with 5,10,15,20-tetrakis(pyridin-3-yl)-21H,23H-porphine. The crystal structure was determined by single-crystal X-ray diffraction. The porphyrin macrocycle exhibits a saddle-like distortion geometry. The MnIII atom has a six-coordination geometry. Each porphyrin unit links to two neighbouring units to yield a one-dimensional coordination polymer. These chains are further interlinked by hydrogen bonds to form a two-dimensional network. The complex shows red photoluminescence emission bands in ethanol solution, which can be attributed to ligand-to-ligand charge transfer (LLCT) accompanied by partial metal-to-ligand charge transfer (MLCT), as revealed by TDDFT calculations.

scholarly journals Ligand-Metal Charge Transfer Induced via Adjustment of Textural Properties Controls the Performance of Single-Atom Catalysts During Photocatalytic Degradation

2021 ◽  
Author(s):  
Jiaxu Liu ◽  
Yajun Zou ◽  
Daniel Cruz ◽  
Aleksandr Savateev ◽  
Markus Antonietti ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Heterogeneous Catalysts ◽  
Photophysical Properties ◽  
Organic Pollutant ◽  
Textural Properties ◽  
Single Atom ◽  
Single Atoms ◽  
Ligand Charge Transfer ◽  
Kinetic Investigations

Because of their peculiar nitrogen-rich structure, carbon nitrides are convenient polydentate ligands for designing single-atom-dispersed photocatalysts. However, the relation of catalysts textural properties with their photophysical properties and as a result activity in photocatalytic applications is rarely elaborated. Herein we report the preparation and characterization of a series of single-atom heterogeneous catalysts featuring highly-dispersed Ag and Cu species on mesoporous graphitic C<sub>3</sub>N<sub>4</sub>. We show that adjustment of materials textural properties and thereby metal single atoms coordination mode enables ligand-to-metal (LMCT) or ligand-to-metal-to-ligand charge transfer (LMLCT), a property tha was long speculated in single-atom catalysis but never observed. We employ the developed materials in the degradation of organic pollutant under irradiation with visible light. Kinetic investigations under flow conditions show that single atoms of Ag and Cu decrease the amount of toxic organic fragmentation products, while leading to a higher selectivity towards full calcination. The results correlate with the selected mode of charge transfer in the designed photocatalysts and provide a new understanding of the surface state of single-atom catalysts. The concepts can be exploited further to rationally design and optimize other single-atom materials.

scholarly journals Light driven isomerization of coordinated ligand and modulation offac-[Re(CO)3(phen)(trans-bpe)]PF6photoluminescence in rigid media

2001 ◽  
Vol 3 (3) ◽  
pp. 143-164 ◽  
Author(s):  
Melina Kayoko Itokazu ◽  
André Sarto Polo ◽  
Neyde Yukie Murakami Iha
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Photophysical Properties ◽  
Acetonitrile Solution ◽  
Solid Films ◽  
Spectral Changes ◽  
Rhenium Complex ◽  
Photostationary State ◽  
Ligand Charge Transfer ◽  
Enhanced Luminescence

The excited state reactivity and photophysical properties offac-[Re(CO)3(phen)(L)]PF6(phen = 1,10-phenanthroline, L =trans- orcis-1,2-bis(4-pyridyl)ethylene, bpe) in PMMA (poly(methyl methacrylate)) films have been investigated and compared with those in acetonitrile solution.313 or 365 nm irradiation of the rhenium complex in PMMA leads to UV-vis spectral changes due to thetrans→cisisomerization of the coordinated bpe ligand. Thefac-[Re(CO)3(phen)(cis-bpe)]+product presents a markedly enhanced luminescence due to a lower lying metal-to-ligand charge transfer (MLCT) excited state in thecisisomer. This emitting property can be conveniently applied as a probe or sensor.Thecisis omer ratio in the photostationary state (PSS) is substantially smaller in solid films than in solution. The photochemical behavior of the freetrans-1,2-bis(4-pyridyl)ethylene in PMMA is also reported to establish comparisons with the investigation carried out in acetonitrile solution as well as with the behavior of the coordinated ligand.

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